Fiber and Nanofiber Spinning Method

ABSTRACT

The present invention relates to a method for spinning fibers, or fiberizers, using a rotary fiber-making die system made up of thin plates, embodied by a housing fixture, configured and stacked to define slots, channels and/or grooves through which the material used to make the fibers will flow. The die system allows for the production of different size and types of fibers, including nanofibers having a diameter of less than 1 micron, and facilitates a variety of cost effective methods for extrusion. The use of plates means the dies can be manufactured cost effectively, with easier clean-outs, replacements and/or variations.

CROSS-REFERENCE TO RELATED APPLICATIONS

This present application is a divisional of Non-Provisional patentapplication Ser. No. 11/635,839, filed on Dec. 8, 2006, which isincorporate herein by reference in its entirety.

BACKGROUND OF THE INVENTION

This invention relates to a method and an apparatus for spinning fibers,or fiberizers, using a rotary fiber-making die system made up of thinplates, embodied by a housing fixture, configured and stacked to defineslots, channels and/or grooves through which the material used to makethe fibers will flow. The die system allows for the production ofdifferent size and types of fibers, including nanofibers having adiameter of less than 1 micron, and facilitates a variety of costeffective methods for extrusion. The use of plates means the dies can bemanufactured cost effectively, with easier clean-outs, replacementsand/or variations.

Thermoplastic resins and glass have been extruded to form fibers andwebs for many years. The nonwoven webs produced are commercially usefulfor many applications including diapers, feminine hygiene products,medical and protective garments, filters, geotextiles, insulation,ceiling tiles, battery separator media and the like. Larger glass-typefibers have been utilized in applications such as acoustical or thermalinsulation materials. The common prior art methods for producing glassfiber insulation products involve producing glass fibers from a rotaryprocess. A single molten glass composition is forced through theorifices in the outer wall of a centrifuge or spinner, producingprimarily straight glass fibers. Curly glass fibers as taught in U.S.Pat. No. 2,998,620 to Stalego, which is incorporated herein byreference, discloses a bi-component glass composition to effect thecurly end product.

A highly desirable characteristic of the fiber used to make nonwovenwebs for certain applications is that they be as fine as possible, insome cases where fibers less than 1 micron are required. Fibers withsmall diameters, less than 10 microns, result in improved coverage withhigher opacity. Small diameter fibers are also desirable since theypermit the use of lower basis weights or grams per square meter ofnonwoven. Lower basis weight, in turn, reduces the cost of products madefrom nonwovens. In filtration applications small diameter fibers createcorrespondingly small pores which increase the filtration efficiency ofthe nonwoven.

The most common of the polymer-to-nonwoven processes are the well knownspunbound and meltblown processes. Some of the common principles betweenthese two processes are the use of thermoplastic polymers extruded athigh temperatures through small orifices to form filaments, using air toelongate the filaments and transport them to a moving collector screenwhere the fibers are coalesced into a fibrous web or nonwoven. Theprocess chosen depends on the starting material and/or on the desiredproperties/applications of the resultant fibers.

In the typical spunbound process the fiber is substantially continuousin length and has a fiber diameter in the range of 20 to 80 microns. Themeltblow process typically produces short, discontinuous fibers thathave a fiber diameter of 2 to 6 microns.

Commercial meltblown processes as taught by U.S. Pat. No. 3,849,241,incorporated herein by reference, to Butin, et al., use polymer flows of1 to 3 grams per hole per minute at extrusion pressures from 400 to 1000psig and heated high velocity air streams developed from an air pressuresource of 60 or more psig to elongate and fragment the extruded fiber.The typical meltblown die directs air flow from two opposed nozzlessituated adjacent to the orifice such that they meet at an acute angleat a fixed distance below the polymer orifice exit. Depending on the airpressure and velocity and the polymer flow rate the resultant fibers canbe discontinuous or substantially discontinuous.

U.S. Pat. Nos. 4,380,570, 5,476,616 and 5,645,790, incorporated hereinby reference, all further detail the melt blowing process. Moreparticularly, they detail improvements to melt blown spinnerettescounted on the surfaces of a polygonal melt-blowing extrusion die blockthereby spinning fibers away from the center of the polygon at highextrusion rates. The fibers being deflected about 90 degrees by an airstream from a circular or polygonal air ring to enhance fiberentanglement and web formation.

Nonwoven webs as taught by Fabbricante et al. U.S. Pat. No. 6,114,017,which is incorporated herein by reference, are made by a meltblownprocess where the material is extruded through modular dies. The patentutilizes a series of stacked plates, each containing one or more rows ofdie tips. Each modular area being attached to a forced air mechanism toeffect an extrusion. This produces a unique nonwoven web similar toFabbricante et al. U.S. Pat. No. 5,679,379, which is incorporated hereinby reference and which details an embodiment of die plates for fiberextrusion. Advantages mentioned by the modular die extrusion methodbeing the efficiency of a quick change if a die became clogged or ofusing a lower cost material to effect a cost advantageous rapidcleanout/changeout.

Conventional melt spinning processes involve molten materials (typicallya polymer and/or glass) being gravity fed or pumped under pressure to aspinning head and extruded from spinneret orifices into a multiplicityof continuous fibers. Melt spinning is only available for polymers (notincluding glass) having a melting point temperature less than itsdecomposition point temperature, such as nylon, polypropylene and thelike whereby the polymer material can be melted and extruded to fiberform without decomposing. Other polymers, such as acrylics, cannot bemelted without blackening and decomposing. Such polymers can bedissolved in a suitable solvent of typically 20% polymer and 80%solvent. In a wet solution spinning process, the solution is pumped, atroom temperature, through the spinneret which is submerged in a bath ofliquid (e.g. water) in which the solvent is soluble to solidify thepolymeric fibers. It is also possible to dry spin the fibers into hotair, rather than a liquid bath, to evaporate the solvent and form a skinthat coagulates. Other common spinning techniques are well known and donot form a critical part of the instant inventive concepts.

The area of fiber spinning frequently involved a spinneret made from asolid metal which is extrusion die cast or drilled to create openings ororifices from which the fibers are extruded. This presents limitedoptions in the fiber spinning area due to a limitation ondistribution/flow paths. A typical spinning method is disclosed in U.S.Pat. No. 5,785,996 to Snyder, which is incorporated herein by reference,and details a glass making invention with a spinning head comprised ofdrilled or machined holes to spin out the fibers. The fibers being aidedin movement by the centrifugal force and/or by sending pressured airthrough the system.

After spinning, the fibers are commonly attenuated by withdrawing themfrom the spinning device at a faster speed than the extrusion speed,thereby producing fibers which are finer and, depending upon thepolymer, possibly more crystalline in nature and thereby stronger. Thefibers may be attenuated by melt blowing the fibers, that is, contactingthe fibers as they emanate from the spinneret orifices with a fluid suchas air. The air being under pressure to draw the same into fine fibers,commonly collected as an entangled web of fibers on a continuouslymoving surface, such as an internal or external conveyor belt or a drumsurface, for subsequent processing.

The extruded fibrous web may be gathered into sheet, tube or roll formwhich may be pleated to increase the surface area for certain filteringapplications. Alternatively, the web or fibers may be gathered togetherand passed through forming stations, such as calendaring rolls, steamtreating and cooling stations, which may bond the fibers at their pointsof contact to form a continuous porous element defining a tortuous pathfor passage of a fluid material.

While earlier techniques and equipment for spinning fibers have commonlyextruded one or more polymer materials directly through an array ofspinneret orifices to produce a web of monocomponent fibers or a web ofmulticomponent fibers, recent developments incorporate a pack ofdisposable distribution or spin plates juxtaposed to each other, withdistribution paths being either etched, grooved, scored, indented, lasercut or slotted into upstream and/or downstream surfaces of the plates todirect streams of one or more polymer materials to and through spinneretorifices at the distal end of the spinning system. Such a mannerprovides a reasonably inexpensive way to manufacture highlysophisticated spinning equipment and to produce a high density ofcontinuous fibers formed of more than one polymeric material. As anexample, a spinning fiberglass die lasts typically 100 hours inproduction, therefore reducing the cost of this production method willprovide financial savings to the user.

One embodiment of current spinplate technology involves circular dieswhich are cast or drilled with a straight extrusion path. Control overthese expensive dies is limited. Such a die is typically made from ablock of steel which various channels and die tips required fordirecting flow of molten polymer are machined, cast or drilled. In orderto reduce the degree of metal working needed, in many cases othermachined blocks of steel are conjoined to the basic die body to carrythe thermoplastic or other fluids required by the particular extrusionprocess. As extrusion dies grow larger and more complicated due to theuse of multiple thermoplastic melts and drawing fluids, the complexityof machining increases geometrically as well as the costs formanufacturing the die.

Another factor adding to the costs of using such dies is the need forfrequent cleaning of the residual carbonaceous matter created by theoxidation of the thermoplastics due to high temperature. This requiresthe availability of additional dies as spares. Dies also have limitedlife due to the erosion of the die tip tolerances due to the hightemperatures and the wear of the fluids flowing through the dies underhigh pressures. An interchangeable and cost effective die which allowsfor a variety of configurations is desired in the art.

SUMMARY OF THE INVENTION

The present invention is directed to a fiber spinning device whichincorporates a series of one or more thin plates configured and stackedto define slots, channels and/or grooves to create a path through whichmaterial flows to form the fibers. Thus, the stacked plates define theoutflow (or die extrusion) edge of the spinning device. The plates canbe stacked into the housing in a manner allowing for variousconfigurations of flow paths, and are typically made from thin sheet,low cost materials allowing for a versatile and cost effective spinningmethod.

The present invention provides a fiber spinning device mountable torotate on a shaft in a fiberizer comprising: one or more stacked, thincircular plates, a housing unit containing the one or more plates, atleast one of the plates or the housing unit having a central opening toreceive material to be formed into fibers, at least one of the plateshaving an outflow edge peripheral to the plate, the one or more platesand housing unit cooperating to form a chamber for receiving the fiberforming material and to allow the flow of material along a radial pathwhereby said outflow edge will define a spinneret orifice through whichfibers can be extruded.

The present invention also provides a method of spinning fiberscomprising the steps of: providing a material for use in forming fibers,providing a fiberizer with a spinneret capable of being spun about ashaft comprising one or more stacked, thin circular plates, providing ahousing device containing the one or more plates, at least one of theplates or the housing unit having a central opening to receive materialto be formed into fibers, at least one of the plates having an outflowedge peripheral to the plate, the one or more plates and housing unitcooperating to form a chamber for receiving the fiber forming materialand to allow the flow of material along a radial path whereby theoutflow edge will define a spinneret orifice through which fibers can beextruded, delivering the material to said spinneret with a rotatingmeans, moving the material through said spinneret and utilizing theplates so as to define a distribution path, extruding the material viaan outflow edge located on one of the plates and peripheral to theplate, and collecting the spun fibers.

The present invention also provides an apparatus for spinning fiberscomprising: at least one source of fiber forming material, a spinneretcomprising one or more stacked, thin circular plates, at least one ofthe plates having a central opening to receive material to be formedinto fibers, at least one of the plates having an outflow edgeperipheral to the plate, said plates cooperating to form a chamber forreceiving the fiber forming material and to allow the flow of materialalong a radial path whereby said outflow edge will define a spinneretorifice through which fibers can be extruded, means for transportingfiber making material to the spinneret, means for axially rotating thespinneret where the rotating means is on the same axis as the centralopening, and means for collecting and removing the fibers formed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 a and FIG. 1 b are a drawing showing the supply means, theoperation of the spinning apparatus and the takeaway means. FIG. 1 adetails a gravity fed supply means. FIG. 1 b details a pressurizedextruder type supply means.

FIG. 2 is a drawing detailing the internal workings of the spinningapparatus with gas being blown at a high velocity, attenuating thefibers as they exit the spinning head;

FIG. 3 is a drawing detailing the internal working of the spinningapparatus with a suction or vacuum method drawing the fibers exiting thespinning head onto a substrate;

FIG. 4 is a drawing detailing the serpentine flow pattern effected bystacking the plates, the material flowing from the central opening tothe outflow edges;

FIG. 5 is a drawing of a fiber making plate and a space plate similar tothose used in FIG. 4;

FIG. 6 are two drawings of the spinning device with two different typespinning plates, FIG. 6 a showing similarly stacked plates and FIG. 6 bdetailing separate concentric chambers of a stacked plate design;

FIG. 7 is a drawing of the spinning plates tilted at an angle from theaxis of rotation;

FIG. 8 is a drawing showing various plates used;

FIG. 9 is a drawing of one embodiment of the plate design detailing twofiber making plates and a spacer plate;

FIGS. 10 a and 10 b are drawings of the takeaway means of the system, inwhich FIG. 10 a is a side view, with part of it being broken away, andFIG. 10 b is a top view; and

FIG. 11 is a drawing of another embodiment of the takeaway means fromthe apparatus, this embodiment detailing a continuous takeaway.

DETAILED DESCRIPTION OF THE INVENTION

The present invention generally relates to an apparatus for extrudingand spinning fibers and relates more particularly to the production of ahomogeneous web of fibers. The plate configuration on the apparatus isof particular importance, as it allows production of nanofibers andother larger fibers by centrifugal force. The stacked, thin plates andthe interchangeability of these plates, along with the variations ofslots, holes or grooves for extrusion of fluid materials is novel to theart of spinning fibers. The device operates by stacking the plates andallowing a serpentine flow for an even, uniform pressure balance andimproved fluid distribution. Stacked, “bridged” plates with smallserpentine flow throughways can also be strategically constructed asbuilt-in filters to material passing through the plates. Theinterchangeability aspects of the plates allows for a variety ofconfigurations to be employed. These variations include, but are notlimited to, changing the size of the extrusion, changing the RPM speedof the spinning head/shaft, altering the fiber diameter, altering thevolume of the extrusion, varying the pressure of the device, or varyingthe temperature extrusion. For the purpose of this invention a fiberizeris known by its common term in the art, that being a device whichproduces fibers.

The present invention allows a variety of flow patterns/distributionpaths. This pattern/path can be easily altered by changing the spinningplate configuration, whereas the prior art die method does not easilyallow changes due to the complexities and costs in manufacturing such asetup. Particularly with serpentine flow, stacked plate assemblies,through conventional milling and drilling would be impossible tomachine.

The plates of the device are easily separated to allow cleaning of theextrusion path if clogging occurs during use. As the material movesthrough the extrusion channel or slots, the plates and/or spacers allowfor cleaning by removal of the plates. This cleaning may be requiredduring normal operation, or may be needed during temperature variationsif the feed material did not melt/process as expected. Such a methodprovides a more cost effective and easier clean out method thanconventional dies. If a situation exists where wear is high, adisposable plate or module assembly may be a viable alternative. Alikely candidate for this type of module would be an extrusion in anabrasive environment. Utilizing a low cost material and a low costmethod for creating the module, several spinning plate combinationscould be preassembled. As the plates become clogged or wear out, themodule is simply discarded; minimizing the amount of time the system isdown for turnaround/production.

Another benefit of the invention is the use of slots or grooves as thepassage channel, canal, or distribution path. Such a setup is unique tothe field, with no known art employing a spinning device withslots/grooves. The current state of the art involves mechanicalstamping, and/or electrical discharged machine (EDM) slots and/orgrooves being etched/cut from a laser or other applicable device. Oneadvantage of the plate method over the current state of the art is thatthe plates of the invention may allow for serpentine flow patterns.Utilizing a series of stacked plates or a series of offset plates allowsa user the ability to create varied flow patterns in the distributionchannel. Such patterns yield better fluid distribution and pressurebalance.

As stated prior, the spinning method of the invention utilizes stackedplates versus standard milled and/or drilled dies from “start-up” block,steel components. The invention provides a spinning head which is lowerin cost and offers much faster delivery of material to the fibernonwoven web production. The invention also allows more circumferentialorifices per linear inch as the stack/height varies and allows for moreversatility of orifice sizes, for more interchangeability and theability to withstand high pressure. With this invention, there is nolimitation regarding plate thickness, slot size, groove size or stackheight.

Referring now to the drawings, FIG. 1 a details a drawing of thespinning apparatus and takeaway means. The main part of the apparatuscomprising a spinning head 2, detailed in FIG. 1 a. The head operates byrotating about a cylindrical shaft 4, as material is gravity fed in asupply means 5 next to the shaft 4, the material enters the spinninghead 2 and is centrifugally forced to the edge, allowing for anextrusion of the material at various diameters of said spinning head 2.The unit is kept under a constant temperature by a heating devicelocated on the source material storage area 6, or the extruder 8, withheat being used to allow for proper flow of the material. The flow ofmaterial in this embodiment is typically by gravity feed only as low oratmospheric pressure is used. A driving pulley 11 or similar system, anda rotation motor 12, detail the rotational means which creates thecentrifugal force for the process. The rotational motor 12 can bevariable to allow for different flow rates of material. In additionvarious types of centrifugal device can be utilized.

FIG. 1 a details the substrate take away means 14 which can be acontinuous belt carrier where fiber is sprayed or discharged onto thebelt, removed from the belt and wound into a roll, or can be fiberssprayed or discharged onto a substrate carrier and wound, or can bedownstream fibers from another source such as meltblown, spunbound orspunlaced acting as a carrier. The substrate take away means 14 in FIG.1 a does not include the fiber web, as the web is added after passingthe spinning head 2. After passing the spinning head, the substrate takeaway means 16 carries the final web product.

FIG. 1 b details the same apparatus as FIG. 1 a, with an alternateconfiguration for the material supply means. The material can also befed under pressure from an extruder 3. The material flows from theextruder 3, to a rotary flange 10. The rotary flange 10 attached to theextruder 3, and the shaft 4. The rotary flange 10, being a flow throughflange having two flanges combined. One flange being stationary, andattached to the extruder 3, the other being rotational and attached by ameans to the rotational motor 12. The shaft 4, in this example having aninner chamber to allow the flow of fluid therein. The rotational motor12 can be variable to allow for different flow rates of material. Theutilization of the gravity feed system of FIG. 1 a and the pressurizedextrusion system of FIG. 1 b is dependent on the application. The twoembodiments are readily interchangeable means of delivering the materialto the spinning plates.

The spinning head 2, has at least one circular plate. The spinning head2 typically consists of a housing device which contains at least onecircular plate. The plate(s) being stamped, machined, etched, scored,laser cut, or indented into a path to which material can flow. At theplate edges, openings are created to allow the material to be deliveredto the substrate takeaway means 16 and create the fiber web. An openingcan be a full plate thickness opening through which the material canpass, or can be a partial plate thickness opening. Such a partialopening can be stamped, machined, etched, scored, laser cut or indentedinto the surface. The partial opening can be on one or both sides of theplate. The use of the partial or full opening is determined based on theapplication. The spinning head 2, contains the plates and also is thearea wherein the extrusion occurs. The substrate takeaway 16 allowingfor extruded material to be eventually wound into a roll or otherstorage means. The fibers are centrifugally extruded from the spinninghead 2, onto the substrate takeaway means setup 14. The substratetakeaway means 16, is the mode/method onto which the fiber web is blown,extruded, gravity fed or pulled by vacuum onto a takeaway means. Inorder to adequately move the materials, a forming tube 18, forms thesubstrate into a cylinder near the spinning head 2. The forming tube 18,forms the substrate and/or the takeaway belt into a cylinder, and fromthere the fibers are spun onto the belt/substrate 14.

FIGS. 2 and 3 detail the internal workings of the spinning apparatus.FIGS. 2 and 3 detail the central location of the plates, and showsmaterial moving through the supply means 5, along the shaft area 4, andeventually into the center of the plate. From there centrifugal force25, moves the material from the center area through the plate to theouter edge and eventually to an extruder type opening on the outflowedge. The material exits the spinning device via this opening. From theopening, a takeaway means delivers the material to its final location.

FIG. 2 details the current state of the art for fiber blowing, such ameans is used in fiberglass blowing. In FIG. 2 higher velocity gases areblown into the center of the spinning head 2. The gases approach thespinning head via a gas inlet 20. This high velocity gas 21, aids inmoving the material thru the device, to the outflow edge and onto thesubstrate carrier. The fibers 22, are attenuated as they exit thespinning head 2 and specifically the stacked plates 24 of the spinninghead 2. This high velocity gas 21 action creating a flow pattern whichthe fibers 22, follow. The velocity of the gas may vary as needed. Inthis embodiment the direction of material flow 23, through the supplymeans 5, is in the same direction 21, as the direction of flow of theattenuated fibers.

FIG. 3 details an embodiment of the apparatus employing a vacuum/suctiondevice. The device is mounted so as to draw air away from the unithousing the spinning device 2 and plates 24. The drawing of this airthru the outlets 26, creates a flow which draws the fibers 22 outwardonto the takeaway means 28. FIG. 3 shows the takeaway means 28 as beinga substrate device which carries the fibers 22 to the final storagelocation. The takeaway means 28, operating in the opposite direction 27,of the material flow 23, from the supply means in this embodiment. Also,FIG. 3 details the tube 30 device which is created by the substratecarrier. Here the tube 30 constricts down in a circular manner aroundthe spinning head 2. The vacuum from the outlets 26, causes the materialto draw away from the outflow edge of the spinning plates 24 and ontothe takeaway means 28 created by the support tube 30.

FIG. 4 details the stacked plates 24 used in the spinning apparatus. Twodifferent types of plates are used in this embodiment, a fiber makingplate 40, and a spacer plate 42. In most embodiments the plates arestacked in an alternating manner with a spacer plate 42, next to a fibermaking plate 40. This process being repeated as needed. However, anotherembodiment involves the use of two fiber-making plates with each platedoubling as a spacer plate or the offsetting of two fiber making platesto effect a divergent flow pattern.

Also detailed in FIG. 4 is the flow pattern involved in one embodimentof the invention. As the material leaves the storage area and extruderthe material travels through the supply means 5, along the shaft 4, thematerial entering a central cavity or central opening 32, locateddirectly adjacent the shaft 4. The material travels from the centralopening 32 and by centrifugal force 25, is drawn into the spinningplates 24. The material being drawn from the center of the spinningplates 24, 40, 42 to the outer edge. At the outermost edge of thespinning plates 24 is an outflow edge 34. Such an outflow edge 34, beingan opening through which the material exits and becomes a fiber and/ornanofiber.

The spinning plates 24 are attached to the shaft 4 by the plate holderdevice 36. The plate holder device 36 encasing the spinning plates androtating with the unit. At the end opposite the rotational shaft 4 is aplate holder end cap housing 38. The end cap housing being a solid platewhich prevents further flow of material and forces the material to exitvia the outflow edge 34. The plate holder device 36 and plate holder endcap housing 38 are also known collectively as a housing unit. Typicallythe material used in constructing the plate holder device 36 and end cap38 (or housing unit), is thicker than the spinning plates 24. Thisallows for higher pressures in the apparatus.

The spinning plates 24 are further defined in FIG. 5 as fiber makingplates 40 or as spacer plates 42. The fiber making plates 40 and spacerplates 42 are typically derived from stamped, machined, laser cut,etched, scored, indented or electrical discharged machining methods. Incases where the alteration does not go though the entire thickness ofthe plate the fiber making plates 40 and spacer plates 42 may be markedor altered on either one or both sides of the plate. The fiber makingplate 40 is circular with a center hole or central opening 32. Thecenter hole 32 allowing for material to be continually fed from thesupply means 5. The fiber making plate 40, typically has a series ofholes or slots 44 radiating from or near the center hole 32 to theoutflow edge 34. These orifices, holes or slots 44 can be slotted,etched, laser cut, scored, indented or electrical discharge machined.The profile of this orifice can be square, rectangular, round, slotted,half round or triangular “V” grooved. The orifices 44 are configured invarious manners to allow varied configurations of the fiber web.Variations on the orifices 44 allow for varying qualities, quantitiesand distribution of fibers in the web. The size of the orifice varieswith dimensions as small as 0.0005″ by 0.0005″. The number of theorifices 44 per linear inch varies with each application but can be from1 to 300 orifices per circumferential inch. In applications where theorifices are small enough and placed close together there can be up to660 orifices per linear inch. In order to achieve this value theorifices must be as small as 0.0005″ wide by 0.0005″ deep and must bespaced 0.001″ apart. When employed in combination, a variety of plateswith differing orifice sizes and orifice numbers can be used. Also thespacing is specific to the application in question.

As stated previously, the orifices 44 radiate outward to an outflow edge34. The outflow edge 34 allows for the escape or extrusion of materialfrom the spinning head 2 and into the take away means 28. The outflowedge 34 typically employs a concentric tip 46. Such a concentric tip 46is made by mechanical, chemical or electrical methods.

The spacer plate 42 in FIG. 5 typically has less area than the fibermaking plate 40, as the purpose is to effect a diversion in the normalflow path of the material. The material following a distribution pathaltered by the insertion of varying spacer plates 42, offset fibermaking plates 40 or differently configured fiber making plates 40. Thespacer plates 42 are typically manufactured by stamped, machined, lasercut, etched or electrical discharged machining methods. If fluidpassageways or distribution channels 48 are needed in the spacer plates42, these channels can be made by slotted, etched, laser cut, scored orindentation methods and can be square, rectangular, slotted, round, halfround or triangular “V” grooves.

The thickness of the fiber making plate 40, and the spacer plate 42,will vary, but in one embodiment the thickness was between 0.0005″ and0.1″. In another embodiment the thickness of these plates varied between0.001″ and 0.1″. For the purposes of this application, the term “thin”is intended to mean plates having a thickness of between about 0.0005inch and 0.1 inch. The plates themselves are typically made from ferrousor non-ferrous metals but can also be made from plastic, ceramic,inconel or any other suitable materials. Advantages provided by the useof a ceramic plates involves less wear and the ability to withstandhigher temperatures. When combining plates a variety of thicknesses canbe used as it is not necessary to use one standard plate thickness. Thedistribution path created by these plates will vary based on theapplication but can be as low as 0.010″ long and 0.0005″ deep by 0.0005″wide.

The plates, as detailed in FIG. 4 and FIG. 6 are stacked with the shaft4, of the apparatus passing thru the central opening 32, of the spinningplates 24. The shaft 4, rotates and creates a centrifugal force 25,moving the material 7, from the supply means 5, into the chamber createdby the central opening 32. The material is transported into the spinningplates 24, through the plates, through the outflow edge 34, and thenoutside the apparatus to the takeaway means 28. The fiber is aided ontothe takeaway means by either a vacuum draw, centrifugal means or a highvelocity gas. The high velocity gas introduced into the system via thegas inlet 20 at the side of the apparatus. The high velocity gas in oneembodiment encircling the spinning plates in a halo or ring 56. The gasflowing from the ring 56 attenuating the fibers into a free fall ontothe takeaway means. The gas exiting the halo ring 56 via a narrowopening 57.

As shown in FIG. 4 the distribution path created by the plates can be,but is not limited to, a serpentine path. Such a path is achieved by thestacking of dissimilar plates 40, 42, or by offsetting similar plates.These methods creating a variety of plate, path and flow configurationsallowing for variations of the fiber diameter, fiber strength and/orconfiguration in the fiber web. In a serpentine setup the pressure ismore uniform and the plates can also be strategically constructed to actas a filter for material. One goal of plate arrangement involvesimproved fluid distribution and pressure balance. In one embodiment theplates are held together by a series of bolts, however any suitablefastening means can be used as a securing means. One such fasteningmeans includes a narrow top to bottom strip weld of the stacked plates.The plate arrangement 24 is secured in the plate holder device 36 to theend cap housing plate 38. The end cap housing plate 38 prohibitingfurther flow of the material thru the center channel and in essenceforcing the material to the outflow edges 34. The housing unit 36, 38thicknesses varying depending upon the temperature and pressureapplication requirement.

The mechanism to spin the fibers has a speed which can vary from 50 to20,000 revolutions per minute. Varying the speed of this device 12, or asimilar device will affect the amount/qualities/diameters of theresultant fiber. Also changing the fluid viscosity, via the heater or bychanging chemical/flow properties of the source material will affect thefiber amount/qualities/diameters.

The basic setup for the spinning plate 24 arrangement is for similarsized plates to be stacked on top of one another, such a configurationis detailed in FIG. 6 a. Another embodiment of the fibermaking platesinvolves a stacked/stepped configuration, as shown in FIG. 6 b. Thisembodiment involves changing the size of the inner diameter of thecenter opening 32. The center opening 32 of the plates at the materialentry end 50 would be wider than the center opening 32 of the plates atthe top or end-cap end 52. Moving from the material entry end 50, to theend cap end 52, the central opening 32 of the plates 24 becomesprogressively smaller. The largest diameter center opening 32 would benear the opening/entry end 50, channeling/stepping down to the smallestinner diameter opening 32 at the end cap 38 or end furthest from theentry end 52. Such a setup would incorporate a blocking plate 54. Theblocking plate 54 being a solid plate of the same diameter of theadjacent plate. The blocking plate 54 prohibits the flow of materialthrough the plate and in essence creates separate zones of extrusion.Such an apparatus would allow better pressure distribution and flowthrough the fiber making system. For example, one embodiment is a seriesof plates 24 with an inner diameter for the central opening 32, of 15″near the entry end 50. Immediately adjacent to these plates would be aseries of plates 24 with a 14″ inner diameter for the central opening32, and immediately adjacent to this would be a series of plates 24 witha 13″ inner diameter for the central opening 32. Here each level isdedicated to extruding the material, but the pressure distribution andflow improves versus a standard straight flow channel.

The angle of the spinning plates 24 in the module is typically at a 90degree angle to the rotational shaft 4. However, as shown in FIG. 7, inorder to create a variation in the lay down of the fibers 22, the angleof the spinning plates 24 can be altered from 0.1 to 20 degrees fromthis typical position, i.e. being at a 70 to 89.9 degree angle to therotational shaft 4. Such an alteration creates a wider spread of fibers22, and allows the take away system to run at a faster rate than astandard 90 degree angle rotating member take away speed.

Various types of plates are used to achieve different purposes. FIG. 8details the various types of plates which can be used to effect thefinal product. A chamber separator plate, or blocking plate 54 is usedto separate zones of flow from one another. Such a plate is solid andallows passage of material only through its central opening 32. Such aplate is useful in a stepped type system as shown in FIG. 7. A spacerplate 42 can have a variety of configurations as shown in FIG. 8 such asa plate with support tie bars 60. Either setup allowing for space to beplaced between adjacent plates. Each plate allowing for passage of fluidvia the central opening 32. Finally the plate setup must include plateswith an outflow edge 34. Such an edge can occur on a plate havingsingle-face channel grooves 62, double faced channel grooves 90 or canbe slotted 64.

FIG. 9 details another embodiment of the spinning plates 24. In thisconfiguration two fiber making plates 40 are shown with a spacer plate42. The central opening 32 or paths for material flow can be seen inboth the top and bottom plates. One embodiment of the invention involvesmaking the spinning plates 24 from a low cost or disposable material.This would allow frequent changes of the spinning plates 24 in areaswhere the device is prone to clogging and for applications wherechanging the plate would be quicker or more cost effective than acleanout. The plates utilize a channel or a slotted configuration as anoutflow edge 34. The plates detailed in this and other embodiments canbe aligned or offset as warranted by the application and final product.

Alternate embodiments of the spinning plate configurations are possible.One option is for openings/orifices to be rectangular, square,triangular, and/or round. Another option allows the user to vary thedifferent number of plates. Another option is to separate the plates byone, two or more spacer plates, the preferred embodiment involving aspacer plate alternating with a fiber making plate. Every embodimentrequires an end cap plate 38. Such a plate being solid and preventingflow of material through. The entire apparatus being secured into aplate holder device 36 which secures the various plates together.

FIGS. 10 a and 10 b detail an embodiment of the collection systemtake-away means. The drawing details a belt or conveyor substrate 14which accepts the fiber material and transports it away 71, from thespinning head 2. The fiber 22 is sprayed, vacuum assisted, blown ordrawn onto the substrate 14, 16. The substrate 14 being passed near thespinning head 2 and then taken away for storage. The speed and tensionat which this takeaway occurs is important, as variations can affect thequality and tensile properties of the fiber. A supply roll 70 ofsubstrate material such as a polyester, polypropylene or any suitablecarrier material allowing the fiber/nanofiber the ability to form anonwoven web to bond, or easily release is needed. This supply rollpasses near the spinning head 2, is kept at a constant diameter at theforming tube 18, which can remain in a tube form or can be mechanicallyor electrically slit to open and then taken to a rollup or storage roll72.

FIG. 10 b defines the conical nature of the takeaway with theperspective shown in FIG. 10 a being a side view. FIG. 10 b details thetakeaway means 16 and substrate carrier 14, expanding into a flatapparatus allowing the fiber mesh to create a web-like sheet 74. Suchtakeaway means 16, can be, but are not limited to, a method of blowingthe fibers or a method that can be pulled under a vacuum.

Another embodiment involves a continuous belt fiber takeaway. The areadescribed as FIG. 11 details a dual purpose continuous carrierembodiment of the takeaway belts. In such a setup continuous carrierbelt 76, moves with or without a substrate 14. Fibers are sprayed onto asupply roll 70, of a material means. The fibers are sprayed onto thismeans 70, as the substrate passes near the spinning head 2. A continuouscarrier belt 76, is powered by a drive motor 78. The continuous carrierbelt operating as a loop, requiring no changes or starting/stopping ofthis belt 76. The substrate of the takeaway means 16, next peels/stripsthe nonwoven material away 22, and winds the nonwoven material into aroll 80, for storage/use.

The source material used for fiber making can be, but is not limited toglass, polymer or thermoplastic materials. Organic polymer materialsmade from sugar and corn can be used. In the prototype embodiment,polypropylene was used as the source material. The prototype materialwas heated and spun under temperature, however it is also possible tocold spin a raw material if the materials chemical properties/makeupallow for flow at room temperature or less than room temperature.

The typical end product created can be, but is not limited tosubstrates, nonwoven media, geotextiles, insulation and other areaswhere fiber is the primary end product.

The delivery of the material from the raw material source 6, to thefiber spinning plates 24, can be gravity fed or can be fed underpressure. Such a pressure can be, but is not limited to, 1 to 500atmospheres. The pressure in the spinning apparatus distribution pathand/or the outflow edge 34, can also be at atmospheric pressure or from1 to 500 atmospheres.

The diameter of spinning head 2, will vary based on application andmethod of use. The diameter of spinning head 2 being within the range of0.1″ to 145″ dia, or within the range of 1.5″ to 50″ dia, or being withthe range of 2.5″ to 12″ dia. The takeaway tube 18, which envelops thedevice can be from 0.5″ to 200″ inside diameter or can be from 3″ to 54″inside diameter or can be from 8″ to 24″ inside diameter. The preferredembodiment utilizing a 3.5″ spinning head 2, with a 12″ takeaway tube18. However, many variations are possible on these setups based on thefinished product desired. For example for flat goods requiring a 120″sheet a spinning head utilizing a 35″ diameter (approximate) isrequired.

The temperatures of the extrusion will also vary based on applicationand method of use. The melt and flow point of the material being usedwill dictate the optimum temperature for extrusion. In one embodiment atemperature of 450 to 500° F. was utilized to properly affect thematerial flow of polypropylene. As stated previous the heater is used toaffect the flow properties of the source materials and is only needed toeffect flow, serving no other apparent purpose. Provided the materialhas the ability to flow at room temperature (or even lower than roomtemperature) spinning is possible. The only limitation on temperaturebeing the ability of the material to flow in the spinning means.

1. A method of spinning fibers comprising the steps of: providing amaterial for use in forming fibers; providing a fiberizer with aspinneret capable of being spun about a shaft comprising one or morestacked, thin circular plates; providing a housing device containing theone or more plates; at least one of the plates or the housing unithaving a central opening to receive material to be formed into fibers;at least one of the plates having a groove which defines an outflow edgeperipheral to the plate; the one or more plates and housing unitcooperating to form a chamber for receiving the fiber forming materialand to allow the flow of material along a radial path whereby theoutflow edge will define a spinneret orifice through which fibers can beextruded, and wherein the one or more said plates have holes and arestacked so as to offset adjacent holes in adjacent plates to define anon-linear path; delivering the material to said spinneret with arotating means; moving the material through said spinneret and utilizingthe plates so as to define a distribution path; extruding the materialvia an outflow edge located on one of the plates and peripheral to theplate; and collecting the spun fibers.
 2. The method of claim 1 wherethe one or more plates are made by stamping, machining, etching, lasercutting or electrical discharge machining.
 3. The method of claim 1where the one or more plates have a thickness between 0.0005″ and 0.1″.4. The method of claim 1 where the non-linear distribution path iscreated by slotting, etching, laser cutting, scoring or indenting aseries of square, rectangular, slotted, semi-circular, or v-shapedgrooves in said plates.
 5. The method of claim 1 where the distributionpath is created by slotting, etching, laser cutting, scoring orindenting a series of square, rectangular, slotted, semi-circular orv-shaped grooves on both sides of the plate.
 6. The method of claim 1where the groove is created by mechanical, electrical or chemicalmethods.
 7. The method of claim 1 where the distribution path has adimension of 0.0005″ to 0.1″ height by 0.010″ to 1.0″ depth by 0.0005″to 0.1″ width.
 8. The method of claim 1 where the one or more plates aremade from ferrous metal, non ferrous metal, aluminum, steel, iron,plastic, inconel or ceramic materials.
 9. The method of claim 1 whereinthe pressure is from 1 to 500 atmospheres.
 10. The method of claim 1wherein the one or more plates are at an angle of 70 to 89.9 degreesfrom the axis centerline.
 11. The method of claim 1 wherein the one ormore plates are stacked in such a manner as to offset any hole from thehole of any adjacent plate.
 12. The method of claim 1 where the plateshave a central hole having an inner diameter of the varying dimensions,with the plate possessing the largest inner diameter being placed nearthe material entry and the plate with the smallest inner diameter platebeing the most remote plate relative to the location of the materialentry so that the series of holes will define a narrowing opening. 13.The method of claim 1 wherein collecting the spun fibers comprises acontinuously fed looped belt system to transport the fibers from theoutflow edge to a storage means.
 14. The method of claim 1 where the oneor more plates are prearranged as an interchangeable module.
 15. Themethod of claim 1 where the one or more plates are disposable.
 16. Amethod for producing fibers comprising: supplying a material from asource for use in forming fibers; delivering said material into afiberizer with a spinneret, said spinneret capable of being spun about ashaft comprising one or more stacked, thin circular plates, having anoutflow edge peripheral to said plates, wherein said plates allow theflow of material in a non-linear distribution path and along a radialpath; spinning said spinneret to extrude said material via said outflowedge peripheral to said plates; and collecting said fibers.